E-mail Links Go To Wrong Place

Ok, I'm having a few problems with my E-mail link on my forums, when ever it send me a link ''so and so has replied'' it posts the link as

http://www.domain.com/forums/index.php/ etc
which errors

any idea's?

[Steve Machol]

SouthYorkieLad, please go to this page and enter your username, to show you are licensed. (you will need to use your customer number and password to access that page)
Thank you.